Pin form for crowns and the like



May 4,1926. 1,583,459

' T. C. HANSEN PIN FORM FOR CROWNS AND THE LIKE Filed April 28, 1925 Patented May 4, 1926. I I UNITED, STATES PAT N F 1 Application filed April 28, 1925." 7 Serial N o.'26, 479.

T '0 all whom it may concern:

Be it known'that If, THOMAS 1 C. HANsEN,

a citizen of the UnitedStates, residing at Caney, in the county of Montgomery and State of Kansas, have invented certain new and useful Improvements in Pin F orms for Crowns and the like, of which the following is a full, clear, and exact description.

Porcelain crowns, such as'the S. S. \Vhite, Justi, Twentieth Century, Davis, Groslee, etc., are usually mounted on the tooth root by means of pins of base metal which are furnished with the crown. Considerable trouble is incurred in attaching these crowns to the teeth, for the reason that the metal pin is weakened by overheating when the cope is cast thereon. Furthermore, an excessive amount of gold was used, for the reason that the wax cope became hopelessly distorted unless made of substantial thickness. And, again, it was practically impossible to cast a thin cope to a metal pin, due to the fact the metal of the pin cooled the molten metal and caused a-nimperfect castmg.

An object of the present invention is to overcome the foregoing objectionable features in fitting crowns, inlays, etc, by pro viding a thin cope and hollow pm of celluloid or similar combustible material which may be readily conformed to the root and crown and then burned out and cast in the usual manner. a

Another object of the invention resides in the provision of a pin such that the same may be readily engaged and removed by means of the sprue, and also in the provision of a pm which, thoughof normal size, 1

yet contains aminimum of material, there by practically I eliminating distortion to the investment when the mold is burned out or exploded.

A further object of the sists in the provision of hollow celluloid pins or tubes to be employed generally in casting operations in dentistry, whether it.

be lingual bars, crowns, inlays, bridge work 01 other construction peculiarto the dental art. v 1 Other objects'and advantagesof the in= vention will be apparent from the following description when taken in connection with the accompanying drawings, in which Figure 1 is an enlarged perspective view of the hollow celluloid pin and cope attached.

invent-ion con- Figure 2 is a viewflsimilar to Figure 1 showing. the wax attached. a Figure 3 isa11 enlarged perspective view of a slightly-modified form of pin. c 1

:Figure 4:is,a sectional view-ofgainold with pin and cope in position.

sections respectively of a pin .employedfin connection with'aninlay.

Figures 7 and 8 are side elevations and sections respectively of a finished pin crown. Figures 9 and 10 are sectionalviews of a pin and cope as applied to aporcelain dummy to be used inbridge work or the like.

lciigure 11 is an'end view of a lingual bar, an

Figure 12 is a side elevation of a tube to be used in vcasting lingual bars. It should be noted that the various figures of the drawing are merely illustrative of a few of themany uses to which my invention may be put, and thatit is, therefore, not

my intention to be limited to the specific embodiments shown, except in so far as such limitations may be embodied in the ap pended claims.

Referring to the and mores-specifically to. Figures 1, 2, 4, b and 6, the numeral 1 indicates a hollow pin of celluloid or similar combustible 'material to which is attached a relatively, thin celluloid cope 2. When fitting this construc tion to a root to be crowned, wax'3 may be applied to the upper or lower surface of the cope 2, as found desirable, and the ends of the pin closed by wax 4. The crown is then removed and a sprue 5, as indicated in Figuref6, is attached to the wax 4 in the outer end of the pin for the purpose of removing the pattern and placing the same in the mold 6, Figure 4. The mold is then burned out in theusual way and the molten metal poured in to form the casting.

In Figure 3 I have shown a celluloid pin 7 which is similar in all respects to the disclo- 'Figuresfi and :6 are side elevations and.

drawing more in detail,

. l'is emcated by the numerals 10 and'11,-,respective-' -1y, Figure 8, while numeral 12 indicates a porcelain dummy to which the flanged celluloid pin 13 may be fitted. A still further form is shown in Figure 10, in which the pin form 1 is fitted to the porcelain dummy 14;.

In Figure 11 I have shown a completed have described what I now believe to be the best embodiment of the invention, but I do not wish to be understood thereby as limiting myself or the scope of the invention, as many changes and modifications may be made without departing from the spirit of the invention; all such I aim to include in the scope of the appended claims.

What I claim as new and desire to secure 20 by Letters Patent is:

l. A pattern to be used in casting dental work, including a hollow pin of combustible material.

2. A pattern to be used in casting dental 25 work, including a hollow celluloid pin.

3. A pattern to be used in casting dental work, including a hollow pin and cope of combustible material. r

4, A pattern to be used in casting dental 3 work, including a hollow pin and cope of celluloid.

THOMAS C. HANSEN. 

